Deadly avalanches hit western US

Colorado Department of Transportation (CDOT) workers watch
a shell fly out of a truck-mounted 'Avalauncher' to trigger
an avalanche near Vail, Colorado earlier this month.
REUTERS/Rick Wilking/Files

Fresh powder in the US West has lured thousands of
skiers, snowboarders and snowmobilers to the high country at a
time the risk of avalanches has been heightened by weather
patterns that are making the snowpack less stable, winter
recreation experts said.

Avalanches have killed 15 skiers and snowmobilers in Western
states in less than two months - well over the nine deaths
recorded in the same period last year - most recently when a
massive slide raced 1400 feet down an Idaho mountainside and
killed a snowmobiler at the weekend.

Government specialists say the uptick in killer avalanches
stems in part from unusually dense and wet snows that have
lately blanketed the mountain West after an extended dry
spell weakened a base layer of snow laid early in the season.

"Storms in the past month have placed very strong, heavy snow
on top of a layer that had the consistency of rock salt and
the strength of potato chips. It's always a bad combination,"
said Craig Gordon, forecaster with the Forest Service Utah
Avalanche Center.

Federal avalanche centers in states such as Idaho, Montana
and Colorado have in recent days stepped up warnings to
winter recreationists, whose numbers in the snowy backcountry
have grown in the last decade alongside advances that have
made treks possible to steep winter terrain that was once
nearly inaccessible.

US avalanche deaths have increased over the past two decades,
hitting a record number of 36 twice since 2007 in seasons
that typically span late fall to late spring, peaking in
January and February, according to federal figures.

Avalanches are common in the snowcapped peaks of the
mountainous West, where 100-yard (91-meter) slides the length
of a football field can travel at speeds of 50 to 250 miles
an hour (80.5 to 402 km an hour). Most deadly avalanches are
triggered by snowmobilers and skiers on federal land in the
Rockies, Cascades and High Sierras that offers prime and
mostly unregulated access to snow.

EXPLOSION OF ACTIVITY

Winter recreation experts link the recent fatalities to gear
advances that allow even the less-skilled to venture into
danger zones.

"A big factor in the spate of deaths in the last month is an
explosion of activity in the backcountry. Bigger, fatter skis
and lighter, faster snowmobiles mean you can go anywhere,
even into harm's way," said Michael Berry, president of the
National Ski Areas Association, a trade group.

US land managers routinely issue avalanche warnings during
winter months but do not prohibit or penalize people for
venturing into avalanche-prone areas at their own risk.

"Powder snow is a powerful drug and it's one a lot of people
can't resist, even when the avalanche danger is high," said
Steve Karkanen, director of the West Central Montana
Avalanche Center.

"In a lot of cases, it takes backcountry skiers and
snowmobilers hours to get to a summit or a high-line ridge,"
he said. "It's a difficult decision to look at a big, long
run and say: 'I'm not going to do it, it's not safe.'"

Land managers advise backcountry recreationists to take
advantage of hazard-mitigating equipment, including
transceivers to pinpoint the location of anyone buried by a
slide, airbags that allow people to float to the surface, and
lighter weight shovels and probe poles used to assess
snowpack structure and locate victims beneath the snow.

Ski resorts across the US West lessen the risks of avalanches
by using explosives to set off slides on unoccupied slopes.
But many developed ski areas in the West are on federal land
and cannot ban skiers from venturing into the backcountry
outside resort boundaries, said the ski association's Berry.

Still, for some, there is no experience equivalent to
out-of-bounds skiing.

"It's a real thrill to go through uncut powder. You're back
there by yourself with fresh snow and no crowds," said Idaho
skier Shannon Page, who sometimes skis in out-of-bounds areas
but said she exercises caution about risks.